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Wednesday, July 20, 2016

The Tipping Point

This is only the beginning. To serious people who read this blog, but may have been confused over the past 5+ years about things like missing heritability, genomic prediction, complex genetic architecture, gloomy prospects: isn't it about time to consider updating your priors? Read all about it here.

Professor Robert Plomin, senior author, called the study “a tipping point for predicting individuals’ educational strengths and weaknesses from their DNA”. It is published in the journal Molecular Psychiatry.

An individual’s “polygenic score” is based on the presence or absence of 20,000 common DNA variants across many different genes. Each has a tiny effect on its own but together they explain 10 per cent of the variation in children’s educational attainment at the age of 16.

It's important to note that 9 percent of variance accounted for implies that the resulting polygenic score predictor would correlate about 0.3 with actual educational achievement. This is similar to the correlation between high school and college grades at a typical flagship state university (note there is some restriction of range) -- not a weak predictor by the standards of social science.

A genome-wide polygenic score (GPS), derived from a 2013 genome-wide association study (N=127,000), explained 2% of the variance in total years of education (EduYears). In a follow-up study (N=329,000), a new EduYears GPS explains up to 4%. Here, we tested the association between this latest EduYears GPS and educational achievement scores at ages 7, 12 and 16 in an independent sample of 5825 UK individuals. We found that EduYears GPS explained greater amounts of variance in educational achievement over time, up to 9% at age 16, accounting for 15% of the heritable variance. This is the strongest GPS prediction to date for quantitative behavioral traits. Individuals in the highest and lowest GPS septiles differed by a whole school grade at age 16. Furthermore, EduYears GPS was associated with general cognitive ability (~3.5%) and family socioeconomic status (~7%). There was no evidence of an interaction between EduYears GPS and family socioeconomic status on educational achievement or on general cognitive ability. These results are a harbinger of future widespread use of GPS to predict genetic risk and resilience in the social and behavioral sciences.